Not quite, but you can come close. I have Cyanogen installed on all my Android devices and I try to use as little proprietary software as possible. However I am patiently waiting for the Neo900, which is a free (libre) hardware design based on the Nokia N900: https://neo900.org/
According to them, there are unfortunately no baseband modems on the market that can legally have their firmware distributed as free software. Their workaround is to keep the modem as isolated from the CPU/RAM as possible.
> According to them, there are unfortunately no baseband modems on the market that can legally have their firmware distributed as free software.
What is the legal restriction here? (It sounds like you're referring to some restriction beyond simple copyright protection on some of their components - are there FCC regulations regarding the firmware?)
EDIT: Ah, of course, the FCC needs to certify devices before they can actually be used.
>We unfortunately cannot provide free baseband modem firmware, as there is no option available on the market which would be able to fulfil this requirement. Even if it existed, it would bring very little value to the users, as operating a radio device with modified firmware on public networks without recertification is prohibited in most jurisdictions of the world and privacy concerns in cellular networks are mostly related to what happens on the network side, not inside the device.
I don't have any more information than this. If someone can quote specific FCC regulations to back this up, I would find that very interesting :)
> Even if it existed, it would bring very little value to the users, as operating a radio device with modified firmware on public networks without recertification is prohibited in most jurisdictions of the world and privacy concerns in cellular networks are mostly related to what happens on the network side, not inside the device.
Not entirely true, publishing the code isn't the same as allowing its modification. Code signing can be used to limit which versions are allowed to run.
Reproducible builds of the source would allow one to ensure that the binary, certified version of the code their baseband processor is running is legit (i.e. not backdoored). It would also help audit the code and spot security holes.
> Not entirely true, publishing the code isn't the same as allowing its modification. Code signing can be used to limit which versions are allowed to run.
If I can't run my home-compiled versions of your code - whether because of code signing restrictions or because of federal law prohibiting firmware that hasn't been certified - it's not free[0]. So without without reproducible builds, providing the source code for the firmware provides very little benefit (since I have no way to prove that the code corresponds to what's actually running on the device, nor any legal way to install and run it on the device myself.)
Reproducible builds could in theory work, but actually getting builds to be bit-for-bit reproducible is not an easy feat. I'd be very surprised if firmware were capable of this.
[0] This is a great example of why a free software license doesn't necessarily mean that the software is free. It means that the author has waived his/her ability to restrict your freedom to use/modify/distribute the software, but that doesn't mean that third parties (ie, the government, or a patent troll) have done the same.
Not free, but open. I'd argue the latter is significantly more important than the former if you're trying to protect against the code working against you. At least if the code is open, you can inspect it and verify its operation.
That's the current state of affairs. I know of no baseband manufacturer who has ever offered (nor seemed open to the idea of releasing) source for their chips.
Basebands aside, the rest of the device is somewhat feasible to see being open.
> Anyone who does is a rounding error.
I'm actually curious if there is literally anyone who uses no proprietary software, including the radios and the SoC, on their Android device.
My bet is that there's not even a single device out there for which this is possible. (If there is, I'd love to see it.)